A researcher is studying facilitated diffusion of a novel solute 'X' across a cell membrane using an artificial lipid bilayer system. They observe that increasing the concentration of X on one side of the membrane increases the rate of transport, but only up to a certain point. Beyond this point, further increases in X concentration do not affect the transport rate. Which of the following BEST explains this observation?
The membrane has reached its maximum permeability for X.
The solute X is being actively transported at higher concentrations.
Saturation of the carrier proteins
The solute X is inhibiting its own transport through feedback regulation.
Related Questions
“Porins” are chemically?
Phospholipids
Carbohydrates
Proteins
Glycolipids
Which of the following is NOT a characteristic of facilitated diffusion?
It requires specific membrane proteins.
It does not require ATP.
It is a passive process.
It moves substances against their concentration gradient.
Aquaporins facilitate the transport of:
Ions
Glucose
Amino acids
Water
In facilitated diffusion, saturation occurs when:
The concentration gradient disappears.
All carrier proteins are occupied by the transported substance.
The cell runs out of ATP.
The temperature decreases significantly.
Which factor does NOT influence the rate of facilitated diffusion?
The concentration gradient of the transported substance
The number of carrier proteins in the membrane
The amount of ATP available
The temperature
Consider the following statements and choose the correct answer
I. Carrier proteins are needed by both facilitated diffusion and active transport and are sensitive to inhibitors that react with protein side chain
II. Different types of proteins present in the membrane plays a major role in both active as well as passive transport
III. The carrier proteins needed by facilitated and active transport are specific
IV. There is no need of energy to pump molecule against a concentration in active transport
V. Transport rate reaches to saturation point, when all the active proteins are used
I, II, II, IV and V
I, II and III
V, IV and I
I, II, III and V
Facilitated diffusion differs from simple diffusion in that it:
Requires ATP
Moves substances against their concentration gradient
Requires membrane proteins
Occurs only in plant cells
The transport of glucose into most animal cells occurs via:
Simple diffusion
Facilitated diffusion using channel proteins
Facilitated diffusion using carrier proteins
Active transport
Which statement can be shared by facilitated diffusion and active transport?
Both need carrier transporter, which are sensitive to inhibitors that reacts with protein side chains
Energy is required by both the processes
No energy expenditure in these processes
Both use carbohydrates to move molecules
across the membrane
Facilitated diffusion involves?
Downhill transport
Without expenditure of energy
Involvement of proteins
All
